length()#

relationalai.std.strings

#length(string: str | Producer) -> Expression

Returns the length of a string. Must be called in a rule or query context.

Parameters#

Name	Type	Description
`string`	`str` or `Producer` objects.	A string or a producer that produces string values.

Returns#

An Expression object.

Example#

#import relationalai as rai
from relationalai.std.strings import length

# Create a model named "people" with a Person type.
model = rai.Model("people")
Person = model.Type("Person")

# Add some people to the model.
with model.rule():
    alice = Person.add(name="Alice")
    bob = Person.add(name="Bob")

# Find the length of each person's name.
with model.query() as select:
    person = Person()
    name_length = length(person.name)
    response = select(p.name, name_length)

print(response.results)
# Output:
#     name  v
# 0  Alice  5
# 1    Bob  3